Bradley F Stewart¹ (), Zachariah Weir¹, Chloe Alvarado¹, Kelly Karagias¹, Ryan V Ringer¹, Carly J Leonard¹; ¹University of Colorado

In a world of abundant sensory stimulation, people must move their eyes to sample the visual environment. Previous studies have shown those with slower saccadic latency during visual search demonstrate higher saccadic accuracy and complete the task with fewer eye movements. In the current experiment, we use well-established measures to understand how attentional and inhibitory functioning relate to these individual differences in oculomotor behavior. A useful field of view (UFOV) task estimated attentional breadth by finding peripheral contrast-sensitivity thresholds, followed by a dual-task block requiring both central and peripheral responses. A saccadic stop signal task (SST) tested inhibitory abilities by asking participants to cancel planned eye movements when a stop signal appears. It was hypothesized that individuals who perform better on the UFOV task would have longer first saccade latencies as they spend more time accumulating peripheral information before initiating their eye movements. Additionally, poor inhibition, as measured by the SST, was predicted to contribute to faster saccade latency, limiting time to accumulate peripheral information before an eye movement decision. The results replicate previous findings showing that individual differences in first eye movement latency were significantly correlated with fixation count and saccadic accuracy during visual search. Regression analyses were conducted to determine which attentional and inhibitory measures predicted oculomotor behavior in visual search. For models of first saccade latency, there was a complex interaction of attentional and inhibitory factors. This was further influenced by a measure indicating how sensitive individuals were to target eccentricity during search. Overall, the results demonstrate that individual differences in eye movements during visual search are at least partially related to variability in attentional and inhibitory functioning as measured by these independent tasks. Nevertheless, further research is needed to investigate what other factors play meaningful roles in determining individual differences in saccadic timing during visual search.

Acknowledgements: Funded by National Eye Institute & Office of Behavioral and Social Science Research (R15EY035056 to CJL).